Powershell: Add/Remove Program entries

Sometimes it is necessary to add an add/remove programs entry. There are instances where an application is independent and requires not installation and you want to make sure it is copied to the system, or you use add/remove programs to verify a service is enabled/disabled. For whatever reason you need to add an entry you want to also add the registry keys so that a WMI query will also detect the entry. The script below will do just that. It creates a GUID, which is required to write the entry in the HKCR key. This is where the WMI will read from, not from the Uninstall directory.

 Function AddRemovePrograms($KeyName, $DisplayName, $Version){  

      #Define Local Memory  
      New-PSDrive -Name HKCR -PSProvider Registry -Root HKEY_CLASSES_ROOT  
      Set-Variable -Name AddRemKey -Scope Local -Force  
      Set-Variable -Name guid -Scope Local -Force  
      Set-Variable -Name ProductsKey -Scope Local -Force 
 
      If (!(Test-Path c:\windows\GSPBox_Icon.bmp)){  
           Copy-Item -Path \\global.gsp\data\clients\na_clients\Build\Add-ins\GSPBox_Icon.bmp -Destination c:\Windows -Force  
      }  
      $AddRemKey = "HKLM:\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall"  
      $ProductsKey = "HKCR:\Installer\Products\"  
      New-Item -Path $AddRemKey -Name $KeyName –Force  
      New-ItemProperty -Path $AddRemKey"\"$KeyName -Name DisplayName -Value $DisplayName -PropertyType String  
      New-ItemProperty -Path $AddRemKey"\"$KeyName -Name DisplayVersion -Value $Version -PropertyType String  
      New-ItemProperty -Path $AddRemKey"\"$KeyName -Name UninstallString -Value " " -PropertyType String  
      New-ItemProperty -Path $AddRemKey"\"$KeyName -Name Publisher -Value "Gresham, Smith and Partners" -PropertyType String  
      New-ItemProperty -Path $AddRemKey"\"$KeyName -Name DisplayIcon -Value "c:\windows\GSPBox_Icon.bmp" -PropertyType String  
      $guid = [guid]::NewGuid().ToString("N")  
      $guid.ToString()  
      $guid = $guid.ToUpper()  
      New-Item -Path $ProductsKey -Name $guid –Force  
      New-ItemProperty -Path $ProductsKey"\"$guid -Name ProductName -Value $DisplayName -PropertyType String -Force  

      #Cleanup Local Memory  
      remove-psdrive -name HKCR  
      Remove-Variable -Name AddRemKey -Scope Local -Force  
      Remove-Variable -Name guid -Scope Local -Force  
      Remove-Variable -Name ProductsKey -Scope Local -Force  
 }